Many present day household refrigerators include a freezer compartment maintained at a below-freezing temperature for the storage of frozen foods and a fresh food compartment maintained at an above-freezing temperature for storage of fresh foods. In many such refrigerators, an evaporator for providing cooling for both the frozen food compartment and the fresh food compartment is positioned outside both compartments and air is circulated over the evaporator and then through the compartments to cool the compartments. The evaporator itself is maintained at a temperature substantially below freezing. In order to maintain the greatly differing temperatures required in the two compartments, a substantially greater portion of the air flowing over the evaporator is directed to the frozen compartment. The air flow over the evaporator and into the freezer and fresh food compartments is controlled by baffles that regulate or reduce the air flow into the fresh food compartment.
In some refrigerators, the evaporator is mounted behind a false partition rear wall in the freezer compartment. The construction of the evaporator behind a rear wall of freezer compartment is shown in U.S. Pat. No. 4,944,157 issued Jul. 31, 1990 to Jenkins et al, U.S. Pat. No. 4,704,874 issued Nov. 10, 1987 to Thompson et al and U.S. Pat. No. 4,077,229 issued Mar. 7, 1978 to Gelbard et al. In each of these patents the refrigerator cabinet has a single cavity liner positioned within an exterior metal shell and a mullion partition divider mounted between the freezer compartment and the fresh compartment. The divider is secured relative to the liner side walls and rear wall. The evaporator is housed behind the false partition wall above the mullion partition.
In other refrigerators, the evaporator is mounted in the partition inserted into the single cavity plastic liner secured relative to the side walls and rear wall of the plastic liner. The construction of the evaporator in the partition divider dividing the single cavity of the refrigerator liner into a freezer compartment and a fresh food compartment is shown in U.S. Pat. No. 3,559,442 issued Aug. 17, 1991 to Robert S. Hanson, U.S. Pat. No. 3,766,976 issued Oct. 23, 1973 to Gelbard et al, U.S. Pat. No. 4,211,090 issued to Gelbard et al, U.S. Pat. No. 4,223,538 issued Sep. 23, 1980 to Braden et al, and U.S. Pat. No. 4,543,799 issued to Oct. 1, 1985 to Horvay et al. While each of these patents locates the evaporator in the mullion partition divider between the fresh food compartment and the freezer compartment, the mullion partition is a separate component of the refrigerator cabinet that is inserted into the liner cavity of the refrigerator and secured relative to the rear and side walls of the liner. The mullion partition has a structural strength limitation that is dependent upon the mechanical fastening of the mullion partition to the rear and side walls of the liner cavity.
There is a need for an evaporator housing to be located within the partition wall between the freezer and fresh food compartments and forms a portion of the partition wall of the refrigerator and where the partition wall is integrally formed with the remainder of the rear and side wall of the refrigerator liner.